1. Field of the Invention
The present invention provides a LED light utilized in the field of indoor horticulture lighting, the light comprising at least three LEDs each emitting light of a different frequency.
2. Description of the Prior Art
High intensity discharge (“HID”) lights have been used in indoor horticulture for many years. Specifically, there are two types of HID lights used for indoor growing: metal halide (MH) and high pressure sodium (HIPS) based systems. MH lights have a blue tint and are typically used during vegetative growth. HPS lights emit a yellowish/red tint used for the flowering portion of the grow process.
The field of light emitting diodes (LED) is a rapidly advancing technology that has the promise to significantly reduce power consumption for general lighting as well as for indoor horticulture. Over the last five years, ever brighter and more efficient LED emitters in the 3-5 W range have been developed which is a significant improvement over the LEDs of 10 years ago that did not exceed 50 mW. When used for indoor growing, LED based lights have the advantage of being higher efficiency than other lights. In addition, LEDs can be focused on the photo-synthetically active regions of the light spectrum, namely blue and red (400-500 nm and 600-700 nm respectively) without wasting energy on the green (500-600 nm) region which is not very useful to plants during the vegetative phase. LEDs emit light in a uni-directional fashion, eliminating the need for reflectors, further improving efficiency. Finally, LEDs have a lifetime of over 50,000 hours compared to less than 10,000 for HID systems, which reduces their overall cost of operation.
Key elements in designing an LED light fixture are:                1. Thermal management: LEDs are most efficient and last longer at lower temperatures.        2. Driver Circuit: LEDs are typically connected in series and driver circuits are typically switching mode power supplies with constant current control.        3. Primary optics (and secondary optics if necessary) to focus the light energy where needed.        
High brightness LEDs (LEDs with power greater than 1 W) are typically mounted on metal core printed circuit boards (MCPCBs). However, MCPCBs are relatively new technology and typically cost three times or more compared to FR4 PCBs (fiberglass based PCBs). In addition, hole plating can not be accomplished with MCPCBs. In this regard, it is difficult to integrate the power supply/LED driver circuit with high brightness (HB) LED on the same MCPCB. Most HB LED light fixtures mount LEDs on an MCPCB then use a separate FR4 based PCB for the power supply/driver circuit resulting in higher assembly costs.
What is desired is to provide an improved LED circuit board for use in indoor plant growing operations, the LED circuit board integrating all the system components on a single PCB and wherein heat generated by the system components is significantly reduced.